1812WBT Surface Mount Wideband RF Transformers Coilcraft 1812WBT Surface Mount Wideband RF Transformers provide wide bandpass performance in a small 1812-sized ferrite body with a ceramic base. The components offer 50V isolation, 1/4W RF input power, and an ambient temperature range of -40°C to +85°C with Irms current. The 1812WBT RF Transformers from Coilcraft feature 1:1, 1.5:1, and 2:1 turn ratio options and RoHS compliant gold over nickel over moly-manganese terminations (other terminations available upon request).